To play aimlessly.
You're fiddling your life away.
To adjust or manipulate for deception or fraud.
Fred was sacked when the auditors caught him fiddling the books.
To play traditional tunes on a violin in a non-classical style.
To touch or fidget with something in a restless or nervous way, or tinker with something in an attempt to make minor adjustments or improvements.
Action of the verb to fiddle
Of petty or trivial importance; footling
It was a fiddling little fault, but ultimately proved disastrous.